1. Field of the Invention
The present invention relates to a fuel filler port closing apparatus provided with a flapper for opening and closing an opening of a nozzle guide for guiding a fuel filling nozzle inserted from an opening of a filler neck (a fuel filler port), the flapper being pushed and biased upwardly by a torsion coil spring and being rotatable downwardly.
2. Description of the Related Art
A filler neck cap screwed into a filler neck has an advantage of being easy to ensure sealability of the filler neck. However, it has a disadvantage in that the attachment/detachment of the filler neck cap is cumbersome. There is also a possibility that sealing may be insufficient if a screw-in operation of the cap is inappropriate or that the detached filler neck cap may get lost. Considering these problems, a fuel filler port closing apparatus provided with a flapper is proposed. Such a fuel filler port closing apparatus has the flapper which opens by rotating downwardly when pushed by the fuel filling nozzle inserted from the outside and closes by rotating upwardly when the fuel filling nozzle is removed. According to the fuel filler port closing apparatus, forgetting to tighten the filler neck cap cannot occur. Further, since the filler neck cap is closed immediately before the fuel filling nozzle is inserted and opens only when the fuel filling nozzle is inserted (i.e., during actual fuel filling task of injecting fuel), discharge of fuel vapor can be suppressed at minimum.
A conventional fuel filler port closing apparatus has a configuration in which an opening at the nozzle guide for guiding a fuel filling nozzle inserted from the opening of the filler neck is opened and closed by a rotating flapper. Specifically, the flapper is attached so as to be pushed and biased upwardly by a torsion coil spring and to be freely downwardly rotatable. The flapper is rotated downwardly when pushed by the fuel filling nozzle inserted from the opening of the filler neck, thereby opens the opening of the nozzle guide. The flapper is rotated upwardly by the torsion coil spring when the fuel filling nozzle is removed, thereby closes the opening of the nozzle guide. Since the opening of the nozzle guide is at a deep position when seen from the opening of the filler neck, dust and rainwater tend to accumulate between the opening of the filler neck and the nozzle guide when the opening of the filler neck is exposed to the outside. This causes dust and rainwater to enter the fuel filling tube when the fuel filling nozzle is inserted and the flapper is pushed and opened. Therefore, the fuel filler port closing apparatus is normally provided with a cover that opens and closes the opening of the filler neck.
The fuel filler port closing apparatus disclosed in DE 20 2007 004 451 U1 is provided with a door (Tur104) that slides by being pushed with the fuel filling nozzle and thereby opens the opening of the filler neck. The door prevents dust and rainwater from entering the opening of the filter neck. DE 20 2007 004 451 U1 is characteristic that a regulation block (Durchlassbereich150) has two projections (150a, 150b) facing each other and spacing a distance that does not pass the diesel filling nozzle but passes the gasoline filling nozzle. The two projections (150a, 150b) are provided on the upstream of the door 104 when seen from the door. This utilizes the fact that the outer diameter of the diesel filling nozzle is larger than the gasoline filling nozzle. When a user moves the fuel filling nozzle towards the door from between the projections of the regulation block 150, only the gasoline filling nozzle can pass between the projections (150a, 150b) and push the door 104. Thus, the possibility of mistakenly filling diesel fuel is eliminated. Since the door 104 is biased in the closing direction, the user needs to insert the fuel filling nozzle into the opening of the filler neck while pushing the door 104 with the fuel filling nozzle that pushed and opened the door 104.